Furnace grate



June 26, 1923.

f E. R. ANDERSON FURNACE `GRATE Filed Feb. 7, 1921 muy #melf/af ffm/f? #nde/15a Patented June 26, 1923..

' unire. srarss .artnr nivrrr. n. nnnnnson, or CHICAGO, rLLrnoIa rumanos GRATE.

v Application filed February 7, 1921. `Serial No. 443,080.

ToaZZ fro/0m t may concern.' i i Be it known that I, EMIL R; AND1; son, a subject of the King of Swedemand resident of the city of Chicago, in the State 1of `lllinois andiUnited States of America,`have invented certain new and` useful Improvements in Furnace Grates, of which the 'fol- `lowing is a `full, clear, and exactdescription.

This'invention relates to improvements in furnace grates and the object of the inventioniis to provide agratewhichmay be very easily operated to clear thesame of ashes and clinlrers.

A further object Iisto provide a grate from which thel refuse is discharged' at the front end of the furnace.

A. still further obj ect is to provide a grate 'which will not be readily burnt out' and which will supply preheated air to the iire.

The invention resides inproviding a pair of similar side plates each having an endless groove therein. ably mounted between the plates in the grooves thereof and means are provided engaging the grate members to' circulate the same in such a manner that' the upper or fire bearing grates move from the back offthe `furnace toward the front, where a pivoted apron is provided to receive refuse yandlalso any good fuel. The apron isprovided with a supporting latch which may be tripped to release the apron to dump refuse into the ash pit. The grate bars are hollow and communicate at their ends with air channels in the side plates, through which air may iiow from the ash pit into the bars and fromthe bars into the furnace. i

. In the drawings which illustrate the in-` ventionr- Fig. 1 is a fragmentary device with parts omitted.

Fig. 2 is a vertical longitudinal section of the device.

Fig. 3 is a vertical cross section of the plan view of the device.

Fig. 4 is a plan view of a single grate unit.

Fig. 5 is a fragmentaryplan view illustrating an alternative formation of the grate bars.

Fig. 6 is a fragmentary plan View illustrating a further alternative arrangement of grate bars.

Referring more particularly to the drawings, 11 designates a pair` of similar side plates adaptedto be supported at opposite sides of a 'furnace in any suitablemanner.

i leading from` the Grate members are slid` Each plate is provided with an endless track groove 12 havingspaced upper and lowery portions and curved end portions connecting them. The plates between the upper and lower portions ofthe 'grooves are provided with air channels 13, to which air` is `ad-.

mitted either through openings `Mfrorn the ash pit or from any other source. Openings 15 are provided at intervals leading from the air channels 13 into the upper `parts of y,

the grooves 12 and openings 16 are provided grooves into the furnace above thegrates. r 1.

The grate bars 17 are preferably tubes of any suitable cross section arranged in series, as

connected at their ends to hollow spacers 18 y having outwardly projecting tubular llugs 119 engageable in the grooves 12 to support the bars. The hollow lugs and hollow spacshown in Figure 4, the bars of each seriesbeing ers permit air flow fromthegrooves into* the bars 17 and from the bars intothe furn nace. These spacers hold the bars a proper distance apart and thus ensure parallelism of the bars andproper spacing to support the fuel and to give adequatedraught. Asl? i shown in Figure 2, ad] acent grate units are in contact, so that an endless grate structure `is formed, the upper portion only of which carries burning fuel while the `lowerportion is idle; A shaft 2O is journalled in the rear ends of the plates 11 and extends transversely of the furnace. Aplurality of sprockets 21 are rigidly mounted `onjthe shaft, the teeth thereof being shaped toengage between the bars 17. An apron-22Y may beprovided at therear end of the device closerto the upper layer of bars and ex-V tending rearwardly thereof to fill the space between the curved end Aof the row of bars and the back of the furnace, in order to l "pivotally mounted a hooked dog 26 adapted to engage an opening 27 in the front plate 241 vand also adapted to pass inwardly rings or sleeves 30 thereon forming spacers ,to hold the bars .aparjt.

i It will be noted in 1* igure 1 that the aperl tures 16 appear in spaced groups in the side plates, the groups of each plate being opposite ythe spaces between groups of the v,other plate. It will also be noted `that the apertures are in similarly spaced groups opposite the groups of apertures 16. This arrangement provides for the admission of heated air in equal amounts onboth sides of the furnace, but it will be understood the openings 16 may ble disposed all in one side plate and the openings 15 allin the other side plate, so that heated air will enter at one side only. In Figure 6 bars are 'shown as connected in series by spacers 31 I through which the ends of the bars may project to have direct engagement with the side plates. When 4three or more bars are connected in series, it is evident that the ends of two only should project into engagement with the side plates, since if more `proyect dif'culty will be experiencedy in passifg the series of groups through the curved portions of the side plate grooves. Theoperation of the device is as follows A fire `is builtl onthe grate in the usual manner and, when it is desired toclean the lire, the shaft yand vsprockets are revolved ina direction .to `cause the lgrate bars to travel toward the front end ,of the furnace,

so that residual material on the bars will be deposited on the apron 28 where the operator can separate good fuel from ashes and clin-kers. When thel apron is suiiiciently loaded with refuse, the retrieving chai-n 28 `lis given a slight upward pull to disengage the dog from the furnace front or the-dog may be ystruck up with a shovel or the operators foot. The apron thenl falls to the vertical position indicated in dotted lines, Figure 2, discharging the refuse intothe ash pit. The apron is replaced in norm-al position by merely pulling on the retrieving chain. The forwardly moving grate bars the top row pass downk at the fron-t end into the lower row and push the bars in the lower row into engagement with the sprockets, sothatblrsfare replaced in the rear end of thefupper row at thesame rate that they are removed atthefrontend, the grate being in effect van endless structure. Any goed; fuel coming forward on to the apron 2 3 may. lbe thrownI to they black end of the furnace. 'Ihe grate may be set in motion only when'desired ormay move slowly and continuously if the system of firing and the fuel permit the same. .A stoker attachment has not been illustrated but if such is used it will be disposed to discharge fresh fuel into therear end of the furnace. use falling between the bars of the upper Refrow will also pass between the bars in the lower row and into the ash pit, very. little refuse, if any, remaining on the lower row of bars. If it is not desired to .thoroughly clean the fire, the grates may bev shaken by oscillating the sprockets, so that the bars will be moved back and `forth rapidly .in

the furnace and any refuse dislodged. Air

flows into the ash pit in the usual manner and is slightly heated by contact with hot refuse therein. Part of this air rises between the grate bars in the Vusual manner and lpart flows into `the air channels 13 of i the side plates and ifrom thence through the hollow bars of the upper row and into the furnace. Preheated air is thus discharged into the furnace `and at the same time `the bars are cooled and prevented from burning.

Vith a grate according to this invention, the work of cleaning -fires and grates is Vgreatly simplified as the fuel and refuse are moved to the front ofthe furnace instead fof to the back, as is customarywith `chain .or endless grates.

Less than half the lbars of the furnace are inuse at one timefso that overheating is prevented and, in addition, the bars carrying fuel are cooled by air flow therethrough so that burning out of bars is entirely eliminated. In the case of separate bars as shown in Figure .5, the bars will revolve to a certain extentl about their axes, so that they do not tend to sag as do bars philch are always in lthesame relation to the ue l Having thus described my inventiomwhat I claim is-: i r

1. In a furnace, a grate comprising a pair of side plates, bars slidably supported therebetween and forni-ing, in effec-t, an endless grate, said bars being hollow to provide air passages therethrough and air passages formed in the side plates connecting the-.air passages kof the b-ars with the ash. pitv and with the fire box of the furnace.

2. In a furnace, a grate comprising a pair of side plates, bars slidabily supported therebetween `and forming, inl effect, an endless grate, said bars being hollow to provide air passages y therethrough and air passages formed. i-n the side plates connecting the air passages of the bars with the ash pit` and with the fire box of the furnace, saidair passages being disposed to conduct air to bothsides of the furnace. i

3. A grate comprising a pair,of side plates, yprovided with air passages, bars 'slidably supported lb etween said plates. and

forming, in effect, any endless grate,` said,

bars being hollow 'to provide, air passages llO lugs in slidable engagement with the saidl plates to support the'bars and to form air inlets and outlets therefor, said lugs being in communication with the passages ofthe side plates.

4. In a furnace, a grate :comprising a pair of side plates, bars slidably supported therebetween and forming, in effect, an endless grate comprising upper and lower layers, means to circulate said grate in suoli a direction that the upper layer moves toward the front of the furnace, an apertured furnace front, an apron hingedly mounted at the front end of the grate to receive material from the bars of the upper layer, a bracket,`

on the apron, a hook pivotally mounted on the said bracket and adapted to engage the furnace front through the opening thereof to support the apron in receiving position, a

retrieving chain connected to said hook to` raise the apron to receiving positiona-nd to draw the hook into operative engagement with the furnace front.

5. A grate comprising a pair of side plates, each of said plates being provided with an endless track groove and with an air passage encircled bysaid track groove and having air inlets, each plate being further provided with spaced passages leading from said first mentioned passage into said track groove and with spaced air passages leading from the track groove and disposed in the spaces between said second, passages and a plurality of hollow grate bars extending between said plates and having open ends disposed in said track grooves.

6. In a furnace, a grate comprising an endless series yof hollow grate bars and guides therefor, the construction comprising means for eecting a circulation of air through said guides and .Orate'bars from the ash pit to the lire boX of the furnace.

7. A grate comprising an endless series of hollow grate bars, guides therefor having endless channels slidably receiving the ends of said bars,`said guides being provided with air passages coacting with said channels to effect a circulation of air through said bars from the ash pit of a furnace to that portion of the furnace above the grate.

8.` A grate comprising a pair of side plates, hollow grate bars slidably supported therebetween and .forming in effect, an endless grate, each of said side plates being provided with an endless groove for said bars, each groove having air inlets in the lower wall of the upperlportion thereof and air outlets in the upper portion thereof above the spaces between the inlets and an air passage formed in each plate encircled by the groove and communicatingwith the air inlets leading tothe groove and air` inlets leading to said passage.

In witness whereof, I have hereunto set my hand.

EMIL R. ANDERSON. 

